Have you seen http://www.sai.msu.su/~megera/postgres/talks/pgcon-2012.pdf ?
On Thu, May 14, 2015 at 9:58 PM, Cory Tucker <cory.tucker@xxxxxxxxx> wrote:
[pg version 9.3 or 9.4]Suppose I have a simple table:create table data (my_value TEXT NOT NULL);CREATE INDEX idx_my_value ON data USING gin(my_value gin_trgm_ops);Now I would like to essentially do group by to get a count of all the values that are sufficiently similar. I can do it using something like a CROSS JOIN to join the table on itself, but then I still am getting all the rows with duplicate counts.Is there a way to do a group by query and only return a single "my_value" column and a count of the number of times other values are similar while also not returning the included similar values in the output, too?